Here's an existing worldwide ban that a bunch of countries already signed: https://en.wikipedia.org/wiki/Treaty_on_the_Prohibition_of_N...
But nuclear powers like United States, Russia, China, North Korea didn't sign it.
Now what? What's the game theory logic that would incentivize a country to disarm its nuclear weapons? Even if a country signs it, how do you monitor every underground missile silo or submarine in the ocean for compliance?
An equally powerful/cost effective weapon that left no radiation damage and no burning city afterwards even if there is still only a crater left.
That way you can have mutual destruction without destroying the rest of the world as collateral. It will be a technology replacement.
You will not loose any strategic capability, meaning you can make progress without the "timed-collective-action-threshold-conditional-commitment" thing that is never going to happen with the incentive structure as its now.
There is no incentive for weapons that can destroy the entire world if the entire world is not aligned, only for weapons that can destroy nations.
That said, this line of thinking makes me sick, while at the same time it seems impossible to me without something similar, you have to make them obsolete.
We need to talk about it more. With 9/11 (and some American attempts to establish nuclear 1st strike doctrine), it sort of fell off the radar. Noam Chomsky always mentions nuclear weapons as the biggest threat to humankind, along with global warming.
We need to emphasize the uselessness/cost of nuclear weapons for rational/moral actors and the risk of irrational actors taking control.
The two largest nuclear arsenals (Russian and American) have been steadily decreasing over past 30 years, but it could happen faster.
I doubt this will ever happen. But maybe in a post-Putin, more democratic (or subdued) Russia we could get there. Not sure how enforcement would work, but a global inspection organization combined with national intelligence capabilities might be sufficient to detect any significant build up. One can dream I guess.
Still safer for the world in general though.